In recent years, there have been provided various devices and systems having a biometric authentication function for performing biometric authentication with use of biometric information indicating physical features such as fingerprints. However, reliability of biometric authentication was not sufficiently high because there were some cases where a forged physical characteristic (for example, a false finger) was erroneously determined as genuine.
Therefore, as a countermeasure against fraudulent authentication using a false finger or the like, living body determination is being performed to determine whether or not the measurement target is a living body. For example, Patent Documents 1 to 4 disclose devices and systems in which living body determination and biometric authentication are performed.
The biometric information measurement device disclosed in Patent Document 1 includes a fingerprint reading device including an image capturing unit that detects a fingerprint pattern, a measurement unit that measures a blood flow velocity of a measurement target, and a calculation unit that determines, based on the measurement result (Doppler shift associated with blood flow velocity), whether or not the measurement target is a living body. The measurement unit is composed of two ultrasonic wave sensors. Each ultrasonic wave sensor is provided with an ultrasonic wave transmitting device and an ultrasonic wave receiving device.
The authentication device disclosed in Patent Document 2 includes a biometric information input unit that collects a fingerprint image of a finger, and a biometric detection unit that collects a blood vessel pattern in the finger by irradiating light to the finger. Based on the collected blood vessel pattern, it is determined whether or not it is a false finger.
The multifactor authentication system disclosed in Patent Document 3 includes a non-spectroscopic biometric information acquisition device that acquires a fingerprint image by image capturing a finger, and a spectroscopic biometric information acquisition device that acquires a diffuse reflection spectrum from the finger. Based on the diffuse reflection spectrum from the finger it is determined whether or not the authentication target is a living body having a predetermined spectroscopic feature.
The image capturing device for forgery determination disclosed in Patent Document 4 includes an image capturing device, a color detection device, a data recording device, a color determination device, and a control device.
The image capturing device color-image-captures a characteristic portion of a subject with visible light and outputs image data for each of a plurality of color components. The plurality of color components are R (red), G (green), B (blue), and NIR (near-infrared). The color detection device detects the color of the characteristic portion from the image data of each color component from the image capturing device.
The data recording device preliminarily holds identification values for identifying the color of the image data of the characteristic portion of the subject. The color determination device identifies the color of the characteristic portion detected by the color determination device and determines whether or not it conforms, based on the color identification value recorded in the data recording device. When the color of the characteristic portion detected by the color detection device does not conforms with the color of the image data recorded in the data recording device, the control device determines the characteristic portion as a forged object.